Geography Commons^™

Active Rock Glaciers Of The Contiguous United States: Geographic Information System Inventory And Spatial Distribution Patterns, Gunnar Johnson, Heejun Chang, Andrew G. Fountain

Geography Faculty Publications and Presentations

In this study we present the Portland State University Active Rock Glacier Inventory (n=10 332) for the contiguous United States, derived from the manual classification of remote sensing imagery (Johnson, 2020; https://doi.org/10.1594/PANGAEA.918585). Individually, these active rock glaciers are found across widely disparate montane environments, but their overall distribution unambiguously favors relatively high, arid mountain ranges with sparse vegetation. While at least one active rock glacier is identified in each of the 11 westernmost states, nearly 88 % are found in just five states: Colorado (n=3889), Montana (n=1813), Idaho (n=1689), Wyoming ( …

Relative Impacts Of Climate Change And Land Cover Change On Streamflow Using Swat In The Clackamas River Watershed, Usa, Junjie Chen, Heejun Chang

Geography Faculty Publications and Presentations

To understand the spatial–temporal pattern of climate and land cover (CLC) change effects on hydrology, we used three land cover change (LCC) coupled scenarios to estimate the changes in streamflow metrics in the Clackamas River Watershed in Oregon for the 2050s (2040–2069) and the 2080s (2070–2099). Coupled scenarios, which were split into individual and combined simulations such as climate change (CC), LCC, CLC change, and daily streamflow were simulated in the Soil and Water Assessment Tool. The interannual variability of streamflow was higher in the lower urbanized area than the upper forested region. The watershed runoff was projected to be …

The Effects On Public Health Of Climate Change Adaptation Responses: A Systematic Review Of Evidence From Low- And Middle-Income Countries., Pauline F D Scheelbeek, Alan D. Dangour, Stephanie Jarmul, Grace Turner, Anne J. Sietsma, Jan C. Minx, Max Callaghan, Idowu Ajibade, Stephanie E. Austin, Robbert Biesbroek, Kathryn J. Bowen, Tara Chen, Katy Davis, Tim Ensor, James D. Ford, Eranga K. Galappaththi, Elphin T. Joe, Issah J. Musah-Surugu, Gabriela Nagle Alverio, Patricia Nayna Schwerdtle, Pratik Pokharel, Eunice A. Salubi, Giulia Scarpa, Alcade C. Segnon, Mariella Siña, Sienna Templeman, Jiren Xu, Carol Zavaleta-Cortijo, Lea Berrang-Ford

Geography Faculty Publications and Presentations

Climate change adaptation responses are being developed and delivered in many parts of the world in the absence of detailed knowledge of their effects on public health. Here we present the results of a systematic review of peer-reviewed literature reporting the effects on health of climate change adaptation responses in low- and middle-income countries (LMICs). The review used the 'Global Adaptation Mapping Initiative' database (comprising 1682 publications related to climate change adaptation responses) that was constructed through systematic literature searches in Scopus, Web of Science and Google Scholar (2013-2020). For this study, further screening was performed to identify studies from …

Broad-Scale Surface And Atmospheric Conditions During Large Fires In South-Central Chile, David B. Mcwethy, René D. Garreaud, Andres Holz, Gregory T. Pederson

Geography Faculty Publications and Presentations

The unprecedented size of the 2017 wildfires that burned nearly 600,000 hectares of central Chile highlight a need to better understand the climatic conditions under which large fires develop. Here we evaluate synoptic atmospheric conditions at the surface and free troposphere associated with anomalously high (active) versus low (inactive) months of area burned in south-central Chile (ca. 32–41° S) from the Chilean Forest Service (CONAF) record of area burned from 1984–2018. Active fire months are correlated with warm surface temperatures, dry conditions, and the presence of a circumpolar assemblage of high-pressure systems located ca. 40°–60° S. Additionally, warm surface temperatures …

Detecting Change In Precipitation Indices Using Observed (1977-2016) And Modeled Future Climate Data In Portland, Oregon, Usa, Alexis Kirsten Cooley, Heejun Chang

Geography Faculty Publications and Presentations

This study addresses how regional changes to precipitation may be identified by exploring the effect of temporal resolution on trend detection. Climate indices that summarize precipitation characteristics are used with Mann–Kendall monotonic testing to investigate precipitation trends in Portland, Oregon (OR) from 1977 to 2016. Observational records from rain gages are compared with downscaled global climate models to determine trends for the historic (1977–2005) and future (2006–2100) periods. Standard indices created by the Expert Team on Climate Change Detection and Indices (ETCCDI) are deployed. ETCCDI indices that summarize conditions at the annual level are generated alongside a limited number of …

Introduction: Managed Retreat And Environmental Justice In A Changing Climate, A. R. Siders, Idowu Ajibade

Geography Faculty Publications and Presentations

In response to global climate change, managed retreat has emerged as a controversial adaptation strategy. The purposeful movement of people and communities away from hazardous places raises numerous social and environmental justice concerns that will become even more pressing as retreat occurs more frequently and at larger scales. This special issue contributes to an emerging body of literature on managed retreat by providing a range of perspectives and approaches to considering justice in managed retreat. The assembled papers represent diverse voices(including perspectives from individuals whose communities are currently relocating or considering relocation), disciplines (including oral histories, legal analyses, and cultural …

Assessment Of Urban Flood Vulnerability Using The Social-Ecological-Technological Systems Framework In Six Us Cities, Heejun Chang, Arun Pallathadka, Jason Sauer, Nancy B. Grimm, Rae Zimmerman, Chingwen Cheng, David Iwaniec, Yeowon Kim, Multiple Additional Authors

Geography Faculty Publications and Presentations

As urban populations continue to grow through the 21st century, more people are projected to be at risk of exposure to climate change-induced extreme events. To investigate the complexity of urban floods, this study applied an interlinked social-ecological-technological systems (SETS) vulnerability framework by developing an urban flood vulnerability index for six US cities. Indicators were selected to reflect and illustrate exposure, sensitivity, and adaptive capacity to flooding for each of the three domains of SETS. We quantified 18 indicators and normalized them by the cities’ 500-yr floodplain area at the census block group level. Clusters of flood vulnerable areas were …

Diagnosing Non-Gaussian Temperature Distribution Tails Using Back-Trajectory Analysis, A. J. Catalano, P. C. Loikith, J. D. Neelin

Geography Faculty Publications and Presentations

Coherent regions exhibiting non-Gaussian 2-m temperature distribution tails are present across the globe, indicating changes in extreme temperatures under future warming may manifest in more complex ways than were the underlying distributions symmetric about the mean. To further the understanding of physical processes that govern temperature distribution tail shape, this work utilizes a back-trajectory model to diagnose mechanisms for extreme daily mean temperature development at select extratropical locations exhibiting non-Gaussian tails. Although characteristics such as direction, distance, and temperature evolution vary among back-trajectories associated with extreme temperature days, results reveal principal pathways for air parcel propagation associated with preferred patterns …

The Influence Of Microsite Conditions On Early Performance Of Planted Nothofagus Nitida Seedlings When Restoring Degraded Coastal Temperate Rain Forests, Jan R. Bannister, Manuel Acevedo, German Travieso, Andres Holz, Nicole Galindo

Geography Faculty Publications and Presentations

Widespread impacts of changes in land use, climate, and disturbance regimes continue to affect mature forests and their subsequent post-disturbance recovery. In South American temperate rainforests, the recovery of the original composition, structure, and ecological services of now-degraded old-growth forests is additionally hampered by the aggressive competition that the native Chusquea bamboo understory exerts on juvenile trees, thus arresting ecological succession. In this study, we aim to evaluate the early performance of Nothofagus nitida seedlings (pioneer tree species that tolerate shade) planted beneath nurse canopy following removal of the understory, and to define which microsite conditions can facilitate N. nitida …

Regulators And Utility Managers Agree About Barriers And Opportunities For Innovation In The Municipal Wastewater Sector, Alida Cantor, Luke Sherman, Anita Milman, Michael Kiparsky

Geography Faculty Publications and Presentations

Despite pressures to improve performance and reduce costs, innovation in the municipal wastewater sector in the United States has been notoriously slow. Previous research has suggested that wastewater utility managers may see regulation as a barrier to developing and deploying new technologies. To better understand how environmental regulation may fuel or hinder innovation in this sector, we conducted a nationwide survey of wastewater utility managers and wastewater regulators in the United States, asking both populations about their perceptions of specific aspects of regulation and innovation. Survey results revealed broad agreement between the two groups that funding and capacity, regulatory relationships, …

Combating Ecosystem Collapse From The Tropics To The Antarctic, Dana M. Bergstrom, Barbara C. Wienecke, John Van Den Hoff, Lesley Hughes, David B. Lindenmayer, Tracy D. Ainsworth, Christopher M. Baker, Lucie Bland, David M J S Bowman, Shaun T. Brooks, Josep G. Canadell, Andrew J. Constable, Katherine A. Dafforn, Michael H. Depledge, Catherine R. Dickson, Norman C. Duke, Kate J. Helmstedt, Andrés Holz

Geography Faculty Publications and Presentations

Globally, collapse of ecosystems-potentially irreversible change to ecosystem structure, composition and function-imperils biodiversity, human health and well-being. We examine the current state and recent trajectories of 19 ecosystems, spanning 58° of latitude across 7.7 M km , from Australia's coral reefs to terrestrial Antarctica. Pressures from global climate change and regional human impacts, occurring as chronic 'presses' and/or acute 'pulses', drive ecosystem collapse. Ecosystem responses to 5-17 pressures were categorised as four collapse profiles-abrupt, smooth, stepped and fluctuating. The manifestation of widespread ecosystem collapse is a stark warning of the necessity to take action. We present a three-step assessment and …

The Value Of Urban Flood Modeling, B. R. Rosenweig, P. Herreros Cantis, Y. Kim, A. Cohn, K. Grove, J. Brock, Heejun Chang, Multiple Additional Authors

Geography Faculty Publications and Presentations

Floods are important disturbances to urban socio-eco-technical systems and their meteorological drivers are projected to increase through the century due to global climate change. Urban flood models are numerical models that have the capability of representing the features of urban ecosystems and the mechanisms of flooding that impact them. They have the potential to play a critical role in flood risk assessment, operational response, and resilience planning, but existing models remain limited in their capability to represent integrated flooding processes in urban areas and provide the credible quantitative information needed to support risk assessment and resilience practice. Research to advance …

Environmental And Spatial Factors Affecting Surface Water Quality In A Himalayan Watershed, Central Nepal, Janardan Mainali, Heejun Chang

Geography Faculty Publications and Presentations

Various spatial interrelationships among sampling stations are not well explored in the spatial modeling of water quality literature. This research explores the relationship between water quality and various social, demographic, and topographic factors in an urbanizing watershed of Nepal with a comparison of different connectivity matrices to conceptualize spatial interrelationships. We collected electrical conductivity and dissolved oxygen data from surface water bodies using a handheld probe and used the data to establish relationships with land use, topography, and population density-based explanatory variables at both watershed and 100-m buffer scales. The linear regression model was compared with different eigenvector-based spatial filtering …

The Right To Urban Streams: Quantitative Comparisons Of Stakeholder Perceptions In Defining Adaptive Stream Restoration, Chang-Yu Hong, Eun-Sung Chung, Heejun Chang

Geography Faculty Publications and Presentations

Assuring healthy streams in the urban environment is a major goal for restoration scientists, urban planners, and city practitioners around the globe. In South Korea, many urban stream restoration efforts are designed to provide safe water to society and enhance ecological functions. We examined the extent to which the individual interests and different values of multiple stakeholders were considered in previous decision-making in two urban stream restoration projects. The relevant data on stream restoration were collected through the nominal group technique (NGT) and the analytic hierarchy process (AHP) for the two stream cases of a populated inland area and a …

High-Severity And Short-Interval Wildfires Limit Forest Recovery In The Central Cascade Range, Sebastian Upton Busby, Kevan B. Moffett, Andres Holz

Geography Faculty Publications and Presentations

Increasing forest fuel aridity with climate change may be expanding mid-to-high-elevation forests’ vulnerability to large, severe, and frequent wildfire. Long-lasting changes in forests’ structure and composition may occur if dominant tree species are poorly adapted to shifting wildfire patterns. We hypothesized that altered fire activity may lower existing forest resilience and disrupt the recovery of upper-montane and subalpine conifer forest types. We empirically tested this hypothesis by quantifying post-fire forest structure and conifer tree regeneration after spatially large, severe, and rapidly repeated wildfires (

A 30-Yr Climatology Of Meteorological Conditions Associated With Lightning Days In The Interior Western United States, Dmitri Alexander Kalashnikov, Paul Loikith, Arielle J. Catalano, Duane E. Waliser, Huikyo Lee, John T. Abatzoglou

Geography Faculty Publications and Presentations

A 30-yr climatology of lightning days and associated synoptic meteorological patterns are characterized across the interior western United States (WUS). Locally centered composite analyses show preferred synoptic meteorological patterns with positive 500-hPa geopotential height anomalies located to the northeast and negative sea level pressure anomalies to the northwest and collocated with local lightning days. Variations in preferred patterns for local lightning days are seen across the interior WUS. Areas not commonly affected by the North American monsoon system including the western Great Basin and northern Rocky Mountains show higher-amplitude anomalies of geopotential height, moisture, and midtropospheric instability patterns suggesting the …

Legal Geographies And Political Ecologies Of Water Allocation In Maui, Hawai'i, Alida Cantor, Kelly Kay, Chris Knudson

Geography Faculty Publications and Presentations

Throughout the Hawaiian Islands, sugar plantations have controlled a large proportion of water resources for over a century, often leaving little water in streams to support ecosystems or Native Hawaiian cultural and agricultural practices. Recently, in Maui, Hawai‘i, community activists and lawyers representing Native Hawaiian and environmental interests have successfully reclaimed water resources for instream flow utilizing legal processes and tools such as Hawai‘i’s public trust doctrine, which has plural roots in both Hawaiian and Western legal traditions. In this paper, we use qualitative fieldwork, including interviews, participant observation, and archival data collection, to explore two recent and ongoing legal …

Dropsonde Observations Of The Ageostrophy Within The Pre-Cold-Frontal Low-Level Jet Associated With Atmospheric Rivers, Rueben Demirdgian, Joel R. Norris, Andrew Martin, F. Martin Ralph

Geography Faculty Publications and Presentations

The pre-cold-frontal low-level jet (LLJ) is an important contributor for water vapor transport within atmospheric rivers, though its dynamics are not completely understood. The present study investigates the LLJ using dropsonde observations from 24 cross-atmospheric river transects taken during the CalWater-2014, 2015 and the AR-Recon 2016, 2018 field campaigns. It is found that the LLJ, located at ;1-km elevation ahead of the cold front, has an average maximum wind speed of 30ms21 and is strongly supergeostrophic with an average ageostrophic component of 6ms21. The alongfront ageostrophy occurs within the atmospheric layer (750–1250 m) known to strongly control orographic precipitation associated …

Associations Of Neighborhood Socioeconomic Conditions With Self-Rated Health, Mental Distress, And Health Behaviors: A Nationwide Cross-Sectional Study In Japan, Tomoya Hanibuchi, Tomoki Nakaya

Geography Faculty Publications and Presentations

Although associations between neighborhood socioeconomic conditions and health have been well established, their geographical scope is mostly limited to Western societies, while multilevel studies in the non-Western context (e.g., Japan) are limited to specific cities/regions within countries. This consequently limits the external validity of the findings. To fill the gap, this study examined the associations between neighborhood socioeconomic conditions and health-related indicators by using nationwide cross-sectional data in Japan. Individual data was collected from a nationwide online survey conducted in 2015 (n = 4593). Self-rated health, mental distress (Kessler Psychological Distress Scale: K6), smoking, and physical activity were analyzed in …

Disturbance Refugia Within Mosaics Of Forest Fire, Drought, And Insect Outbreaks, Meg A. Krawchuk, Garrett W. Meigs, Jennifer M. Cartwright, Jonathan D. Coop, Raymond Davis, Andres Holz, Crystal Kolden, Arjan Jh Meddens

Geography Faculty Publications and Presentations

Disturbance refugia – locations that experience less severe or frequent disturbances than the surrounding landscape – provide a framework to highlight not only where and why these biological legacies persist as adjacent areas change but also the value of those legacies in sustaining biodiversity. Recent studies of disturbance refugia in forest ecosystems have focused primarily on fire, with a growing recognition of important applications to land management. Given the wide range of disturbance processes in forests, developing a broader understanding of disturbance refugia is important for scientists and land managers, particularly in the context of anthropogenic climate change. We illustrate …

Socio-Hydrology: An Interplay Of Design And Self-Organization In A Multilevel World, David J. Yu, Heejun Chang, Taylor T. Davis, Vicken Hillis, Landon T. Marston, Woi Sok Oh, Murugesu Sivapalan, Timothy M. Waring

Geography Faculty Publications and Presentations

The emerging field of socio-hydrology is a special case of social-ecological systems research that focuses on coupled human-water systems, exploring how the hydrologic cycle and human cultural traits coevolve and how such coevolutions lead to phenomena of relevance to water security and sustainability. As such, most problems tackled by socio-hydrology involve some aspects of engineering design, such as large-scale water infrastructure, and self-organization in a broad context, such as cultural change at the population level and the hydrologic shift at the river basin or aquifer level. However, within the field of socio-hydrology, it has been difficult to find general theories …

Associations Of Built Environment Attributes With Bicycle Use For Transport, Mohammad Javad Koohsari, Rachel Cole, Koichiro Oka, Ai Shibata, Akitomo Yasunaga, Tomoya Hanibuchi, Neville Owen, Takemi Sugiyama

Geography Faculty Publications and Presentations

An increasing number of studies have examined neighbourhood built environment attributes associated with cycling. Some of them suggest non-linear relationships between built environment attributes and cycling. This study examined the strength and shape of associations of cycling for transport with objectively measured built environment attributes. Data were from 9146 Australian adults who took part in the 2009 South-East Queensland Travel Survey. Participants (aged 18–64 years) completed a 24-hour travel survey, in which they reported modes of travel. Residential density, Walk Score and a Space Syntax measure of street integration were calculated at a neighbourhood level using geographic information systems. Multilevel …

A Digital Archive Of Human Activity In The Mcmurdo Dry Valleys, Antarctica, Adrian Howkins, Stephen M. Chignell, Poppie Gullett, Andrew G. Fountain, Melissa Carrie Brett, Evelin Preciado

Geography Faculty Publications and Presentations

Over the last half century, the McMurdo Dry Valleys (MDV) of East Antarctica have become a globally important site for scientific research and environmental monitoring. Historical data can make important contributions to current research activities and environmental management in Antarctica but tend to be widely scattered and difficult to access. We address this need in the MDV by compiling over 5000 historical photographs, sketches, maps, oral interviews, publications, and other archival resources into an online digital archive. The data have been digitized and georeferenced using a standardized metadata structure, which enables intuitive searches and data discovery via an online interface. …

Central Tokyo’S Low Response Rate To The 2015 Population Census And Its Related Factors, Tomoya Hanibuchi, Masakazu Yamauchi

Geography Faculty Publications and Presentations

Recently, there has been an increase in the number of “unreported” cases in the Population Census of Japan caused by nonresponses to the survey. Subsequently, this has led to data reliability challenges. In light of this problem, the factors related to the low response rate of the 2015 Population Census in the central Tokyo area are examined in the present study. An online survey was conducted among individuals residing in the three Special Wards of Tokyo to inquire about their responses (submitted or not submitted) to the previous census. The statistical analyses demonstrated that particularly in central Tokyo, middle-aged (35–49 …

Virtual Audits Of Streetscapes By Crowdworkers, Tomoya Hanibuchi, Tomoki Nakaya, Shigeru Inoue

Geography Faculty Publications and Presentations

Audits have been used to provide objective ratings of neighborhood environments. Physical audits, however, are time- and resource-intensive. This study examines the efficiency and reliability of virtual auditing using Google Street View and crowdsourcing to conduct walkability audits of streets in Japan. Overall, 830 street segments were physically and virtually audited by two trained auditors; 300 untrained crowdworkers also virtually audited 3 street segments. Statistical analysis found good inter-source and inter-rater reliability. This study helps establish crowdsourced virtual auditing as a valuable method of measuring neighborhood walkability, reducing audit costs as well as enabling large-scale auditor recruitment while maintaining reliability.

Spatiotemporal Variability Of Twenty‐First‐Century Changes In Site‐Specific Snowfall Frequency Over The Northwest United States, Arielle J. Catalano, Paul C. Loikith, C. M. Aragon

Geography Faculty Publications and Presentations

In the Northwest United States, warming temperatures threaten mountain snowpacks. Reliable projections of snowfall changes are therefore critical to anticipate the timeline of change. However, producing such projections is challenging, as most state‐of‐the‐art climate models are limited in sufficiently resolving influential topography. Here we leverage atmospheric freezing level to estimate precipitation phase and project twenty‐first‐century snowfall frequency change at Snowpack Telemetry Network stations across the Northwest. Under “moderate” and “business‐as‐usual” emission pathways in Coupled Model Intercomparison Project phase 5 models, snowfall frequency is projected to decline at all stations. Business‐as‐usual declines accelerate after midcentury at most locations, whereas moderate declines …

Aligning Endangered Species Management With Fire-Dependent Ecosystem Restoration: Manager Perspectives On Red-Cockaded Woodpecker And Longleaf Pine Management Actions, Shelby A. Weiss, Eric L. Toman, R. Gregory Corace Iii

Geography Faculty Publications and Presentations

Background: Endangered species management has been criticized as emphasizing a single-species approach to conservation and, in some cases, diverting resources from broad-based, land management objectives important for overall biodiversity maintenance. Herein we examine perceptions on management for an endangered species whose habitat requirements largely depend on frequent fire, the red-cockaded woodpecker (Leuconotopicus borealis Vieillot). In doing so, we consider the alignment between species-specific population recovery actions and broader ecosystem restoration goals. Through semi-structured interviews with natural resource professionals (n = 32) in the Southeast Coastal Plain of the United States, we examined manager perspectives on the evolution of recovery …

The Alt-Right And Global Information Warfare, Emmi Bevensee, Alexander Ross

Geography Faculty Publications and Presentations

The Alt-Right is a neo-fascist white supremacist movement that is involved in violent extremism and shows signs of engagement in extensive disinformation campaigns. Using social media data mining, this study develops a deeper understanding of such targeted disinformation campaigns and the ways they spread. It also adds to the available literature on the endogenous and exogenous influences within the US far right, as well as motivating factors that drive disinformation campaigns, such as geopolitical strategy. This study is to be taken as a preliminary analysis to indicate future methods and follow-on research that will help develop an integrated approach to …

Contrasting Local And Long-Range-Transported Warm Ice-Nucleating Particles During An Atmospheric River In Coastal California, Usa, Andrew C. Martin, Gavin Cornwell, Charlotte M. Beall, Forest Cannon, Sean Reilly, Bas Schapp, Dolan Lucero, Jessie Creamean, F. Martin Ralph, Hari T. Mix, Kimberly Prather

Geography Faculty Publications and Presentations

Ice-nucleating particles (INPs) have been found to influence the amount, phase and efficiency of precipitation from winter storms, including atmospheric rivers. Warm INPs, those that initiate freezing at temperatures warmer than −10ºC, are thought to be particularly impactful because they can create primary ice in mixed-phase clouds, enhancing precipitation efficiency. The dominant sources of warm INPs during atmospheric rivers, the role of meteorology in modulating transport and injection of warm INPs into atmospheric river clouds, and the impact of warm INPs on mixed-phase cloud properties are not well-understood. In this case study, time-resolved precipitation samples were collected during an atmospheric …

California Groundwater Management, Science-Policy Interfaces, And The Legacies Of Artificial Legal Distinctions, David Owen, Alida Cantor, Nell Green Nylen, Thomas Harter, Michael Kiparsky

Geography Faculty Publications and Presentations

California water law has traditionally treated groundwater and surface water as separate resources. The 2014 Sustainable Groundwater Management Act (SGMA) broke with this tradition by requiring groundwater managers to avoid significant and unreasonable adverse impacts to beneficial uses of surface water. This paper considers the trajectory of this partial integration of science, law, and resource management policy. Drawing on legal analysis and participatory workshops with subject area experts, we describe the challenges of reconciling the separate legal systems that grew out of an artificial legal distinction between different aspects of the same resource.

Our analysis offers two main contributions. First, …